In the history of the debasement of money in England and France by their governments, we find repeatedly that prices had not risen in the same proportion in which the silver coinage had been debased. That was simply due to the fact that the proportion in which the currency was increased did not correspond to the proportion in which it had been debased; that is to say, because an inadequate quantity of coins of the poorer metallic composition was issued, if the exchange values of commodities were to be estimated in the future in the new coin as a measure of value and be realized in coins corresponding to this smaller unit of measure. This solves the difficulty left unsettled in the controversy between Locke and Lowndes. The ratio which a token of value, whether made of paper or of debased gold or silver, bears to certain weights of gold or silver estimated according to the mint price, depends not on its own composition but on the quantity in which it is found in circulation. The difficulty in understanding this is due to the fact that money in its two functions of a measure of value and a medium of circulation is subject to two not only opposite but apparently contradictory laws corresponding to the difference in the two functions. In the discharge of its function of a measure of value where money serves merely as money of account and gold only as ideal gold, everything depends on the natural substance of money. Estimated in silver or expressed in silver prices exchange values are naturally estimated quite differently than when measured in gold or as gold prices. On the contrary, in its function of a medium of circulation, where gold is not only imagined but is actually present side by side with other commodities, its substance is immaterial and everything depends on its quantity. For the unit of measure the determining factor is whether it consists of a pound of gold, silver or copper; while in the case of coin, no matter what its own composition is, it will become the embodiment of each of these units of measure in accordance with its quantity. But it goes against common sense that in the case of mere imaginary money everything should depend on its material substance, while in that of the palpably present coin all should be determined by an ideal ratio of numbers.